Maryland state prosecutors denied yesterday that partisan politics played a role in prompting their investigation of whether Linda R. Tripp broke the state's wiretapping law, even as Republicans attributed the probe's timing to pressure applied by Democrats.

State Prosecutor Stephen Montanarelli "doesn't make his decisions based on" political considerations, said James Cabezas, the prosecutor's chief investigator.

"We act on our own," Cabezas said.

His comments came a day after Tripp's third appearance before a federal grand jury in Washington, which is focusing in part on her tape-recorded conversations with former White House intern Monica S. Lewinsky.

Tripp accused the Maryland prosecutor of trying to intimidate her. But Montanarelli said Tuesday that he felt it was time to move forward and present evidence to a Howard County jury to determine whether Tripp violated state wiretapping law when she recorded more than 20 hours of phone calls with Lewinsky. Tripp made the recordings in the fall at her Columbia home.

Maryland law requires both parties to consent to taped phone calls. Tripp's recordings represent key evidence in independent counsel Kenneth W. Starr's investigation of whether President Clinton had an affair with Lewinsky and encouraged her to deny it under oath.

Tripp's attorneys said last night on the "Larry King Live" TV interview show that they found the timing of Montanarelli's announcement suspect. One of them, Joe Murtha, a former Howard County prosecutor, said he believes the Montanarelli investigation sends a message that "people who come forward and cooperate in a federal investigation may have a price to pay."

He said that announcing the inquiry just as Tripp is testifying in the federal criminal investigation "does send a subtle message to the grand jurors" in the Starr probe.

Until this week, Montanarelli was content to defer to Starr's investigation before launching his own. Montanarelli was asked five months ago to take over the Tripp case at the request of Howard County's Republican prosecutor, Marna McLendon. Sources familiar with Montanarelli's decision to move forward said the timing was the result of an opening between other unrelated investigations.

Del. Robert L. Flanagan (Howard), the House Republican whip, said although the state prosecutor's office is ostensibly an independent office charged with investigating official corruption, it is still "beholden" to the legislature for its budget.

Montanarelli's timing "raises a lot of legitimate questions, particularly in light of the fact that this whole issue was poisoned by the political involvement of legislators," said Flanagan, referring to a letter signed by more than 40 Democratic lawmakers in February calling for Tripp's prosecution.

Judicial Watch, a conservative foundation that is involved in more than a dozen lawsuits against the Clinton administration, filed a request yesterday under Maryland's Public Information Act seeking from Montanarelli "any and all documents" pertaining to Tripp, Lewinsky, Starr, the White House and others.

Del. Leon G. Billings (D-Montgomery), one of the primary authors of the Democratic letter demanding that Montanarelli investigate Tripp, said he spoke with the state prosecutor about the Tripp case last month but only after Montanarelli called him about another matter. Montanarelli told Billings he was not moving ahead with an investigation at the time.

"I said, 'So when are you?' " Billings said. "And he said, 'When it is appropriate.' He didn't respond to me at all."

"It is very important to the Republicans that they somehow politicize this issue because . . . they are stuck with the fact that a principal in the Clinton investigation broke Maryland law and their own party's prosecutor refused to pursue that violation," Billings said.

On another front, Cabezas and several legal experts said yesterday that any immunity agreement Tripp has with federal investigators would not protect her from prosecution in Maryland.